Multiple filament lamp



Feb. 6, 1945.

G. c. SINGER MULT'IPLE FILAMENT LAMP Filed Dec. 51, 1945 FIGJ. F1612 3652 as 37 y GROYER a. swan.

Patented Feb. 6, i945 UNlTED STATES PATENT OFFICE 6 Claims.

This invention relates to an electric lamp and a method of constructingthe same.

An object of the invention is the provision of an electric lamp-and themethod of making the same, in which the lamp has a solid base memberformed integrally with the globe, with both being formed of transparentmaterials, with the inner surface of the base member, and likewise thebottom of the globe being provided with a reflector, the base memberhaving a longitudinal passage through which are adapted to be insertedfilaments and specially constructed supports for the filaments, saidsupports being secured in place by lead-in wires projecting above theinner surface of the base member.

Another object of the invention is the provision of an electric lamphaving a base member formed of the same transparent materials as theglobe, with a passage through the base member for the insertionofspecially constructed supports and filaments, the inner surface of thebase member, which also forms the bottom of the globe, being coveredwith reflecting materials, said inner surface being concave, convex, orfiat.

A further object of the invention is the provision of an electric lampin which the base and bulb are formed integrally of the same transparentmaterials, said base member having embedded therein wires to which areconnected supports for filaments arranged in the arcs of a circle, saidsupports being in the form of a sleeve adapted to be received by theinner ends of the lead-in wires, with the ends of the lead-in wires bentto secure the sleeves in place, the inner ends of the sleeves beingprovided with a lateral split projection to receive an end of afilament, said supports and filaments being insertable through alongitudinal passage in the base member, and fixed in place by suitabletools which are insertaible through the passage for properly positioningthe supports.

, changes and' modifications as define no material departure from thesalient features of the invention as expressed in the appended claims.

Figure 1 is a horizontal section of an electric lamp constructedaccording to the principles of my invention.

Figure 2 is a vertical section taken along the line 2-2 of Figure 1.

Figure 3 is an enlarged fragmentary vertical section showing the methodof securing a support in place on a lead-in wire.

Figure 4 is a section similar to that shown in 5 Figure 1, but showing amodified form of refleeting urface.

Figure 5 is a vertical section of another modified form of the lampdisclosing anotheriorm of reflecting surface.

Figure 6 is an enlarged plan view of one section of the filaments andtheir supports.

Referring more particularly to thedrawing, It designates a base memberformed of transparent material such as glass, and this base member formsthe bottom, which has the usual threaded sleeve ll attached to a reducedportion i2 so that, the lamp can be screwed into the usual lamp socket.It will be noted that the base-member is integrally formed with the bulbl3 so that it is necessary to insert the filaments and their supportsthrough a central longitudinal passage l4, extending entirely throughthe base member and opening at IE to the inner end of a convex portionit of the base member.

Lead-in wires 20, 2|, 22 and 23 are embedded in the material of the basemember [0, and project upwardly as shown at 24 in Fig. 3, with the innerfree ends of said wires split to form securing elements 25 and 26. Inother words, a sleeve 21 is inserted on the inner projecting end 24 of a'wire and split ends 25 and 26 are placed downwardly over the upper endof the sleeve. If desired. these ends may be twisted to form anenlargement -for retainingthe sleeve 21 in place.

".Sleeve 21 (Figs. 1 and 2) has a lateral extension 28 at its upper endand this extension, as is the sleeve 21, is formed of metal, and issplit to receive one end 29 of a filament 30. The other end of thefilament is received by a split end 3| of a lateral extension at theupper end of a sleeve 32. A second lateral extension -33 is locateddiametrically opposite the extension 3| and is split to receive one endof a filament 34.

A third sleeve 35 is received by a wire 22 and has a split extension 36at its upper end to receive the other end of the filament 34. The postsor sleeves 21, 32 and 35 are so arranged around the inner surface 31 ofthe member in that-the filaments 30 and 34 are located in an arc of acircle at one side of the central passage H in the base member Ill.

A group .of filaments 40 and 4| are supported by hollow posts 42, 43:and 44 at the other side of the passage I4, with the filaments beingarranged in the arc of a circle.

member have been completed, the hollow posts and their connectedfilaments are inserted through the passage ll of the base member and theposts are inserted over the inner ends of the lead-in wires by a'suitable tool and the split ends of the lead-in wires are then twistedor bent down over the posts. After the silvering materials which form areflector 45 have been applied to .ments.

the inner surface of the globe l3, and the base member ID, the lamp isready for exhaustion of the air through the passage M. then closed bythe usual cement to form a sealing plug 46.

Each of the wires 20, 2|, 23 and 23"- is provided with a contact 41 atthe outer end of the base member ID for engagement with a contact in theusual socket of 'the lamp. Wires 22 and 22* extend to the thr ded metalcollar or sleeve II. Thus, it will beseen that the current passesthrough the wires 20 and 2|, also wires 23 and 23 to the filaments,while wires 22 and 22 complete the circuits to the fila- The lamp shownin Fig. 4 is identical in construction with that shown in Figs. 1 and 2,ex-

cept that the inner surface .50 of the base member III is fiat insteadof convex as shown in Figs. land 2. 1

The lamp shown in Fig. 5 is substantially identical in construction asthat shown in Figs. 1, 2 and 4, except that the inner surface 5i of thebase member I is convex. The globe l3 is slightly different in shape,although the same shape of globe may be, employed as illustrated inFigs. 2 and 4.

The method of applying the silvering materials to form the refiector Ais described in my co-lpending application, St'N. 461,978, filed October14, 1942, for Incandescent electric lamps and method of making the same.

Before the silvering materials are applied to the inner surface of theglobe and the base member, melted wax, a solution of beeswax or molassesis applied to the bottoms of the various This passage is etchingmaterials contains the following ingredi-' ents by volume:

Ammonium fluoride parts- Hot water o 18 Molasses do 20 Hydrofiuoric acid"percent-.. 60

Where the filaments and their supports have been positioned before theetching materials are applied to the surface 55 and the surface 31;

said supports and filaments are thoroughly coated with the wax toprotect them against the etching materials.

' Iclaim:

1. An electric lamp, comprising a base, a bulb formed integrally withsaid base, lead-in wires embedded in the base and having split endsextending into the bulb, a vertical sleeve mounted on each split end,the split ends of the wires being arranged to secure the sleeves inposition, said sleeves arranged along an arc of a circle, each sleeve atthe ends of the are having a split lateral projection, the intermediatesleeve having a pair of diametrically disposed split lateralprojections, and a filamentlocated between each end sleeve and theintermediate sleeves, the ends of the filaments being clamped'betw'eenthe adjacent split projections of the sleeves.

- 2. An electric lamp, comprising a base, a bulb formed integrally withsaid base, lead-in wires embedded in the base and having split endsextending into the bulb, the inner surface of the base and a portion ofthe sidewalls ofthe bulb having a reflecting surface thereon, thatportion of the inner surface of the base surrounding the extended endsof the lead-in wires being free hollow posts, and also to the innersurface of the base member l0, surrounding the bottom'of the posts, sothat when the silvering material is applied, such material may be.removed, together with the beeswax or molasses, in order to leave aspace 52 free of silvering material to preventshort circuiting of thecurrent between the posts. The beeswax or the molasses'is applied asdefined by an instrument suitable for the purpose.

7 between the adjacent splitv projections of the of the reflectingsurface, a vertical sleeve mount-- ed on each split end, the split endsof the wires being arranged ,to secure the sleeves in position, saidsleeves arranged along, an arc of a circle, each sleeve at the ends ofthe arc having a split lateral projection, the intermediate sleevehaving a pair of diametrically disposed split lateral projections, and afilament located between each end sleeve and the intermediate sleeve,the ends of the filaments being clamped .sleeves.

Furthermore, molten beeswax, a solution of beeswax or molasses is placedin the outer end of the bulb l3, and the bulb is then revolved to coverthe inner surface 5! of the globe It to the circular line indicated bythe numeral 56.

Etching materials of a well known type are then/placed within the bulband the same is revolved to cover the inner surface located between theinner surface 31 of the base member In and the circular line 58. Theetching materialsare then; removed and. the inner surface i washed,after which the protectivematerials,

including the portions 55 and 52, are removed. The composition which isa solution of the 3. An electric lamp, comprising a base, a bulb formedintegrally with said base, lead-in wires embedded in the base and havingsplit ends ex- -tending into the bulb, two of the wires being v ';hefilaments being secured in place by the fila- I ment gripping means onthe sleeves.

4. An ele'ctric lamp, comprising a base, a bulb extending outwardly fromsaid base, a group of three wires embedded in the base at each side of aplane passing through the longitudinal axis of the lamp and having endsprojecting into the bulb, said ends being arranged in a, circle, avertical sleeve on each projec'ting end, the free ends of the wireshaving means thereon for retaining the sleeves in position, the upperends of the sleeves having lateral projections, and a filament locatedbetween each pair of sleeves at one side of the longitudinal plane andhaving the ends secured to adjacent lateral projections on the sleeves,the filaments being bent to conform to the curvature of the circle."

5. An electric lamp, comprising a base, a bulb extending outwardly fromsaid base, a group of three wires embedded in the base at each side of aplane passing through the longitudinal axis of the lamp and having endsprojecting into the bulb, said ends being arranged in a circle, twoadjacent wires of each group adapted to be placed in circuit with oneside of a source of current, the other wires of each group adapted to beplaced in circuit with the other side of said source, a vertical sleeveon each Projecting end, the free ends of the wires having means thereonfor retaining the sleeves in position. the upper extending outwardlyfrom said base, a group of three wires embedded in the base at each sideprojections on the sleeves, the filaments being bent to conform to thecurvature of the circle. 6. An electric lamp, comprising a base, a bulbof a plane passing through the longitudinal axis of the lamp, and havingends projecting into the bulb, said ends being arranged in a circle, theinner surface of the base and a portion of the inner walls of the bulbbeing provided with a reflecting surface, those portions of the surfaceof the base surrounding the inner projecting ends of the wires beingfree of the reflecting surface, saidbase having a convex surface withthe projecting ends of said wires arranged around the periphery of theconvex surface, a vertical sleeve on each projecting end, the free endsof the wires having means thereon for retaining the sleeves in position,the upper end of the sleeves having lateral projections, and a filamentlocated between each pair of sleeves at one side of the longitudinalplane, and having the ends secured to adjacent lateral projections onthe sleeves, the filaments being bent to conform to the curvature of thecircle.

GROVE-R C. SINGER.

